Huawei U. of California Huawei Huawei This document provides an analysis and evaluation of security with P2PSIP overlay network. The draft compares security difference between C/S and P2P, then partitions the P2PSIP architecture into layers, and analyze the security issues in each layer and the security relationship among the layers. Security issues with different kind of application scenarios are distinct. This draft classifies the application scenarios into two main types, and the security threats with these two types of scenarios are analyzed in detail.